While it is now recognized that the manufacture of nanomaterials may present unique risks to humans and the environment, the field of nanotoxicology remains at an early stage. Nanomaterials, the building blocks of nanotechnology, constitute a very diverse range of compounds. They include low dimensionality materials such as C60 and inorganic nanoparticles (NP), and one-dimensional materials such as carbon nanotubes and the focus of this study, inorganic nanowires (NW). With the exception of studies of carbon nanotubes, most toxicology studies have assessed the impacts of inorganic nanoparticles. There is a growing expectation that inorganic nanowires may be more broadly utilized than other nanomaterials but there is a remarkable lack of safety information on these compounds. We therefore propose a collaboration between environmental chemists and toxicologists to develop the knowledge to minimize the risks of nanowires to human health. We will focus in this proposal on silver nanowires of varying lengths and diameters as a representative of this class of nanomaterials. We will address three inter-related questions in our work. What is the role of the intrinsic physicochemical properties of nanowires on their behavior in different environments? What is the relationship between nanowire properties and the environment on cellular and organismal toxicity? And what are the mechanisms by which nanowires lead to adverse effects in these systems? We propose to develop new approaches for the assessment of nanowire properties and toxicity which could have general applicability for assessment of other nanomaterials of concern. PUBLIC HEALTH RELEVANCE: Nanowires are a form of nanomaterials that are expected to be used in a broad array of commercial and consumer products. Despite their likely wide spread use, there is very limited information on the safety of nanowires. We propose to assess the safety of nanowires using state of the art toxicology approaches.